Journal tags: performance

After I wrote positively about the speculation rules API I got an email from David Cizek with some legitimate concerns. He said:

I think that this kind of feature is not good, because someone else (web publisher) decides that I (my connection, browser, device) have to do work that very often is not needed. All that blurred by blackbox algorithm in the browser.

That’s fair. My hope is that the user will indeed get more say, whether that’s at the level of the browser or the operating system. I’m thinking of a prefers-reduced-data setting, much like prefers-color-scheme or prefers-reduced-motion.

But this issue isn’t something new with speculation rules. We’ve already got service workers, which allow the site author to unilaterally declare that a bunch of pages should be downloaded.

I’m doing that for Resilient Web Design—when you visit the home page, a service worker downloads the whole site. I can justify that decision to myself because the entire site is still smaller in size than one article from Wired or the New York Times. But still, is it right that I get to make that call?

So I’m very much in favour of browsers acting as true user agents—doing what’s best for the user, even in situations where that conflicts with the wishes of a site owner.

Going back to speculation rules, David asked:

Do we really need this kind of (easily turned to evil) enhancement in the current state of (web) affairs?

That question could be asked of many web technologies.

There’s always going to be a tension with any powerful browser feature. The more power it provides, the more it can be abused. Animations, service workers, speculation rules—these are all things that can be used to improve websites or they can be abused to do things the user never asked for.

Or take the elephant in the room: JavaScript.

Right now, a site owner can link to a JavaScript file that’s tens of megabytes in size, and the browser has no alternative but to download it. I’d love it if users could specify a limit. I’d love it even more if browsers shipped with a default limit, especially if that limit is related to the device and network.

I don’t think speculation rules will be abused nearly as much as client-side JavaScript is already abused.

There’s a new addition to the latest version of Chrome called speculation rules. This already existed before with a different syntax, but the new version makes more sense to me.

Notice that I called this an addition, not a standard. This is not a web standard, though it may become one in the future. Or it may not. It may wither on the vine and disappear (like most things that come from Google).

The gist of it is that you give the browser one or more URLs that the user is likely to navigate to. The browser can then pre-fetch or even pre-render those links, making that navigation really snappy. It’s a replacement for the abandoned link rel="prerender".

Because this is a unilateral feature, I’m not keen on shipping the code to all browsers. The old version of the API required a script element with a type value of “speculationrules”. That doesn’t do any harm to browsers that don’t support it—it’s a progressive enhancement. But unlike other progressive enhancements, this isn’t something that will just start working in those other browsers one day. I mean, it might. But until this API is an actual web standard, there’s no guarantee.

That’s why I was pleased to see that the new version of the API allows you to use an external JSON file with your list of rules.

I say “rules”, but they’re really more like guidelines. The browser will make its own evaluation based on bandwidth, battery life, and other factors. This feature is more like srcset than source: you give the browser some options, but ultimately you can’t force it to do anything.

I’ve implemented this over on The Session. There’s a JSON file called speculationrules.js with the simplest of suggestions:

{
  "prerender": [{
    "where": {
        "href_matches": "/*"
    },
    "eagerness": "moderate"
  }]
}

The eagerness value of “moderate” says that any link can be pre-rendered if the user hovers over it for 200 milliseconds (the nuclear option would be to use a value of “immediate”).

I still need to point to that JSON file from my HTML. Usually this would be done with something like a link element, but for this particular API, I can send a response header instead:

Speculation-Rules: “/speculationrules.json"

I like that. The response header is being sent to every browser, regardless of whether they support speculation rules or not, but at least it’s just a few bytes. Those other browsers will ignore the header—they won’t download the JSON file.

Here’s the PHP I added to send that header:

header('Speculation-Rules: "/speculationrules.json"');

There’s one extra thing I had to do. The JSON file needs to be served with mime-type of “application/speculationrules+json”. Here’s how I set that up in the .conf file for The Session on Apache:

<IfModule mod_headers.c>
  <FilesMatch "speculationrules.json">
    Header set Content-type application/speculationrules+json
   </FilesMatch>
</IfModule>

A bit of a faff, that.

You can see it in action on The Session. Open up Chrome or Edge (same same but different), fire up the dev tools and keep the network tab open while you navigate around the site. Notice how hovering over a link will trigger a new network request. Clicking on that link will get you that page lickety-split.

Mind you, in the case of The Session, the navigations were already really fast—performance is a feature—so it’s hard to guage how much of a practical difference it makes in this case, but it still seems like a no-brainer to me: taking a few minutes to add this to your site is worth doing.

Oh, there’s one more thing to be aware of when you’re implementing speculation rules. You have the option of excluding URLs from being pre-fetched or pre-rendered. You might need to do this if you’ve got links for adding items to shopping carts, or logging the user out. But my advice would instead be: stop using GET requests for those actions!

Most of the examples given for unsafe speculative loading conditions are textbook cases of when not to use links. Links are for navigating. They’re indempotent. For everthing else, we’ve got forms.

My colleague Chris has written a terrific post over on the Clearleft blog: Is the planet the missing member of your project team?

Rather than hand-wringing and finger-wagging, it gets down to some practical steps that you—we—can take on every project.

Chris finishes by asking:

Let me know how you design with the environment in mind. What practical advice would you suggest?

Well, here’s something that I keep coming up against…

Chris shows that the environment can be part of project management, specifically the RACI methodology:

We list who is responsible, accountable, consulted, and informed within the project. It’s a simple exercise but the clarity is useful for identifying what expertise and input we should seek from the named individuals.

Having the planet be a proactive partner in your project ensures its needs are considered.

Whenever responsibilities are being assigned there are some things that inevitably fall through the cracks. One I’ve seen over and over again is responsibility for third-party scripts.

On the face of it this seems like another responsibility for developers. We’re talking about code here, right?

But in my experience it is never the developers adding “beacons” and other third-party embedded scripts.

Chris rightly points out:

Development decisions, visual design choices, content approach, and product strategy all contribute to the environmental impact of your website.

But what about sales and marketing? Often they’re the ones who’ll drop in a third-party script to track user journeys. That’s understandable. That’s kind of their job.

Dropping in one line of JavaScript seems like a victimless crime. It’s just one small script, right? But JavaScript can import more JavaScript. Tools like Request Map Generator can show just how much destruction third-party JavaScript can wreak:

You pop in a URL, it fetches the page and maps out all the subsequent requests in a nifty interactive diagram of circles, showing how many requests third-party scripts are themselves generating. I’ve found it to be a very effective way of showing the impact of third-party scripts to people who aren’t interested in looking at waterfall diagrams.

Just to be clear, the people adding third-party scripts to websites usually aren’t doing so maliciously. They often don’t realise the negative effect the scripts will have on performance and the environment.

As is so often the case, this isn’t a technical problem. At root it’s about understanding people’s needs (like “I need a way to see what pages are converting!”) and finding a way to meet those needs without negatively impacting the planet. A good open-minded discussion can go a long way.

So I echo Chris’s call to think about environmental impacts from the very start of a project. Establish early on who will have the ability to add third-party scripts to the site. Do all of those people understand the responsibility that gives them?

I saw this lack of foresight in action on a project recently. The front-end development was going really well and the site was going to be exceptionally performant: green Lighthouse scores across the board. But when the site went live it had tracking scripts. That meant that users needed to consent to being tracked. That meant adding another third-party script to generate a consent banner. It completely tanked the Lighthouse scores.

I’m sure the people who added the tracking scripts and consent banners thought they had no choice. But there are alternatives. There are ways to get the data you need without the intrusive surveillance and performance-wrecking JavaScript.

The problem is that it’s not the norm. “Everyone else is doing it” was the justification for Flash intros two decades ago and it’s the justification for enshittification via third-party scripts now.

It doesn’t have to be this way.

If you’re a fan of gratuitous initialisms, you’ll love Google’s core web vitals. Just get a load of the obfuscation in the important-sounding metrics like CLS, FCP, LCP, and more.

To be fair to Google, this is a problem in the web performance world in general. Practioners prefer to talk about TTFB rather than “time to first byte” even though both contain exactly the same number of syllables.

The big news in the web performance community this month is the arrival of a new initialism. INP sounds like one of those pseudo-scientific psychologic profiles but it’s meant to stand for Interaction to Next Paint (even if they were to swear off pointless initialisms, you’d still have to pry Pointless Capitalisation from Google’s cold dead hands).

This new metric is a welcome one. It’s replacing first input delay. Sorry, First Input Delay, or FID, one of the few web vital initialisms that can be spoken as a word, making it a true acronym (fortunately fid’s successor, inp, also works as an acronym).

First Input Delay has long outstayed its welcome. It was always an outlier in the core web vitals. It didn’t seem to measure anything actually useful. I know it sounds like it’s measuring the delay until the user can interact with a web page, but when you dive into what it actually does, it’s a mess:

FID measures the time from when a user first interacts with a page (that is, when they click a link, tap on a button, or use a custom, JavaScript-powered control) to the time when the browser is actually able to begin processing event handlers in response to that interaction.

See that word “begin” in there? It’s doing a lot of work. First Input Delay doesn’t measure the lag between the user interaction and the browser response; it only measures the lag between the user interaction and the browser beginning to respond. The actual response could take ages, but that lag doesn’t get measured. Unlike the other core web vitals, this metric is very far removed from what actually matters to the user’s experience.

What the fid where they thinking? How the fid did this measurement ever get included in core web vitals in the first place?

Well, feel free to take what I’m about to say as pure gossip, but I have my sources, I trust ’em, and no, I’m not going to reveal ’em…

It’s because of AMP.

Remember Google AMP? An acronym so pointless they eventually just forgot it ever stood for anything?

The AMP project ended up doing incredible damage to Google’s developer relations. By colluding with the search team to privilege the appearance of AMP pages in the top news carousel, Google effectively blackmailed the entire publishing industry into using their format.

In the end, it didn’t work. It was a shit format. All they did was foster resentment and animosity:

AMP seems to have faded away. Most publishers have started dropping support, and even Google doesn’t seem to care much anymore.

It turns out that Google search wasn’t the only team infected by AMP. The core web vitals team also had to play ball.

Originally they had a genuinely useful metric for measuring the lag between input and response. But guess which pages did terribly? That’s right: AMP pages.

Rather than ship an actually-useful measurement, the core web vitals team instead had to include the broken First Input Delay, brainchild of a certain someone on the AMP team.

Now it all makes sense.

So good riddance to FID. Welcome to INP. And here’s hoping it won’t be much longer till we’re finally burying AMP.

I’m at day two of Indie Web Camp Brighton.

Day one was excellent. It was really hard to choose which sessions to go to because they all sounded interesting. That’s a good problem to have.

I ended up participating in:

• a session on POSSE,
• a session on NFC tags,
• a session on writing, and
• a session on testing your website that was hosted by Ros

In that testing session I shared some of the bookmarklets I use regularly.

Bookmarklets? They’re bookmarks that sit in the toolbar of your desktop browser. Just like any other bookmark, they’re links. The difference is that these links begin with javascript: rather than http. That means you can put programmatic instructions inside the link. Click the bookmark and the JavaScript gets executed.

In my mind, there are two different approaches to making a bookmarklet. One kind of bookmarklet contains lots of clever JavaScript—that’s where the smart stuff happens. The other kind of bookmarklet is deliberately dumb. All they do is take the URL of the current page and pass it to another service—that’s where the smart stuff happens.

I like that second kind of bookmarklet.

Here are some bookmarklets I’ve made. You can drag any of them up to the toolbar of your browser. Or you could create a folder called, say, “bookmarklets”, and drag these links up there.

Validation: This bookmarklet will validate the HTML of whatever page you��re on.

Validate HTML

Carbon: This bookmarklet will run the domain through the website carbon calculator.

Calculate carbon

Accessibility: This bookmarklet will run the current page through the Website Accessibility Evaluation Tools.

WAVE

Performance: This bookmarklet will take the current page and it run it through PageSpeed Insights, which includes a Lighthouse test.

PageSpeed

HTTPS: This bookmarklet will run your site through the SSL checker from SSL Labs.

SSL Report

Headers: This bookmarklet will test the security headers on your website.

Security Headers

Drag any of those links to your browser’s toolbar to “install” them. If you don’t like one, you can delete it the same way you can delete any other bookmark.

I’m a little obsessed with web performance. I like being able to check a page’s core web vitals quickly and easily.

Four years ago, I made a Lighthouse bookmarklet. Whatever web page you were on, when you clicked on the bookmarklet you’d get the Lighthouse results for that page. Handy!

It doesn’t work anymore. This is probably because Google are in the loop. Four years is pretty good innings for anything involving that company.

I kid (mostly). Lighthouse itself is still going strong, despite being a Google product. But the bookmarklet needs updating.

Rather than just get Lighthouse results, I figured that the full PageSpeed Insights results would be even better. If your website is in the Chrome UX report, you get to see those CrUX details too.

So here’s the updated bookmarklet:

PageSpeed Insights

Drag that up to your desktop browser’s bookmarks toolbar. Press it whenever you want to test the page you’re on.

I wrote a little while back about improving performance on The Session by reducing runtime JavaScript in favour of caching on the server. This is on the pages for tunes, where the SVGs for the sheetmusic are now inlined instead of being generated on the fly.

It worked. But I also wrote:

A page like that with lots of sheetmusic and plenty of comments is going to have a hefty page weight and a large DOM size. I’ve still got a fair bit of main-thread work happening, but now the bulk of it is style and layout, whereas previously I had the JavaScript overhead on top of that.

Take a tune like Out On The Ocean. It has 27 settings. That’s a lot of SVG markup that needs to be parsed, styled and rendered, even if it’s inline.

Then I remembered a very handy CSS property called content-visibility:

It enables the user agent to skip an element’s rendering work (including layout and painting) until it is needed — which makes the initial page load much faster.

Sounds great! But there are two gotchas.

The first gotcha is that if a browser doesn’t paint the element, it doesn’t know how much space the element should take up. So you need to provide dimensions. At the very least you need to provide a height value. Otherwise when the element comes into view and gets rendered, it pushes down on the content below it. You’d see a sudden jump in the scrollbar position.

The solution is to provide a value for contain-intrinsic-size. If your content is dynamic—from, say, a CMS—then you’re out of luck. You don’t know how long the content is.

Luckily, in my case, I could take a stab at it. I know how many lines of sheetmusic there are for each tune setting. Each line takes up roughly the same amount of space. If I multiply that amount of space by the number of lines then I’ve got a pretty good approximation of the height of the sheetmusic. I apply this with the contain-intrinsic-block-size property.

So each piece of sheetmusic has an inline style attribute with declarations like this:

content-visibility: auto;
contain-intrinsic-block-size: 380px;

It works a treat. I did a before-and-after check with pagespeed insights on the page for Out On The Ocean. The “style and layout” part of the main thread work went down considerably. Total blocking time went from more than 600 milliseconds to less than 400 milliseconds.

Not a bad result for a little bit of CSS!

I said there was a second gotcha. That’s browser support.

Right now content-visibility is only supported in Chrome and Edge. But that’s okay. This is a progressive enhancement. Adding this CSS has no detrimental effect on the browsers that don’t understand it (and when they do ship support for it, it’ll just start working). I’ve said it before and I’ll say it again: the forgiving error-parsing in HTML and CSS is a killer feature of the web. Browsers just ignore what they don’t understand. That’s what makes progressive enhancement like this possible.

And actually, there’s something you can do for all browsers. Even browsers that don’t support content-visibility still understand containment. So they’ll understand contain-intrinsic-size. Pair that with a contain declaration like this to tell the browser that this chunk of content isn’t going to reflow or get repainted:

contain: layout paint;

Here’s what MDN says about contain:

The contain CSS property indicates that an element and its contents are, as much as possible, independent from the rest of the document tree. Containment enables isolating a subsection of the DOM, providing performance benefits by limiting calculations of layout, style, paint, size, or any combination to a DOM subtree rather than the entire page.

So if you’ve got a chunk of static content, you might as well apply contain to it.

Again, not bad for a little bit of CSS!

I’m quite sure this is of no interest to anyone but me, but I finally managed to fix a longstanding weird issue with my website.

I realise that me telling you about a bug specific to my website is like me telling you about a dream I had last night—fascinating for me; incredibly dull for you.

For some reason, my site was being brought to its knees anytime I syndicated a note to Mastodon. I rolled up my sleeves to try to figure out what the problem could be. I was fairly certain the problem was with my code—I’m not much of a back-end programmer.

My tech stack is classic LAMP: Linux, Apache, MySQL and PHP. When I post a note, it gets saved to my database. Then I make a curl request to the Mastodon API to syndicate the post over there. That’s when my CPU starts climbing and my server gets all “bad gateway!” on me.

After spending far too long pulling apart my PHP and curl code, I had to come to the conclusion that I was doing nothing wrong there.

I started watching which processes were making the server fall over. It was MySQL. That seemed odd, because I’m not doing anything too crazy with my database reads.

Then I realised that the problem wasn’t any particular query. The problem was volume. But it only happened when I posted a note to Mastodon.

That’s when I had a lightbulb moment about how the fediverse works.

When I post a note to Mastodon, it includes a link back to the original note to my site. At this point Mastodon does its federation magic and starts spreading the post to all the instances subscribed to my account. And every single one of them follows the link back to the note on my site …all at the same time.

This isn’t a problem when I syndicate my blog posts, because I’ve got a caching mechanism in place for those. I didn’t think I’d need any caching for little ol’ notes. I was wrong.

A simple solution would be not to include the link back to the original note. But I like the reminder that what you see on Mastodon is just a copy. So now I’ve got the same caching mechanism for my notes as I do for my journal (and I did my links while I was at it). Everything is hunky-dory. I can syndicate to Mastodon with impunity.

See? I told you it would only be of interest to me. Although I guess there’s a lesson here. Something something caching.

The Session does very well in terms of performance. You can see the data from the Chrome UX Report (CRUX).

What’s good for performance is good for the environment. Sure enough, The Session gets a very high score from the website carbon calculator:

Hurrah! This web page achieves a carbon rating of A+

This is cleaner than 99% of all web pages globally

But under the details about hosting it says:

Oh no, it looks like this web page uses bog standard energy

The Session is hosted on DigitalOcean, who tend to be quite tight-lipped about their energy suppliers. Fortunately others have done some sleuthing to figure out which facilities are running on green energy.

One of the locations to get the green thumnbs up is the Amsterdam facility housed by Equinix. That’s where The Session is hosted.

I’m glad that I was able to find out that the site is running on 100% renewable energy, but I wish I didn’t need to go searching to find this out. DigitalOcean need to be a lot more transparent about the energy sources for their hosting facilities.

Performance is a high priority for me with The Session. It needs to work for people all over the world using all kinds of devices.

My main strategy for ensuring good performance is to diligently apply progressive enhancement. The core content is available to any device that can render HTML.

To keep things performant, I’ve avoided as many assets (or, more accurately, liabilities) as possible. No uneccessary images. No superfluous JavaScript libraries. Not even any web fonts (gasp!). And definitely no third-party resources.

The pay-off is a speedy site. If you want to see lab data, run a page from The Session through lighthouse. To see field data, take a look at data from Chrome UX Report (Crux).

But the devil is in the details. Even though most pages on The Session are speedy, the outliers have bothered me for a while.

Take a typical tune page on the site. The data is delivered from the server as HTML, which loads nice and quick. That data includes the notes for the tune settings, written in ABC notation, a nice lightweight text format.

Then the enhancement happens. Using Paul Rosen’s brilliant abcjs JavaScript library, those ABCs are converted into SVG sheetmusic.

So on tune pages there’s an additional download for that JavaScript library. That’s not so bad though—I’m using a service worker to cache that file so there’ll only ever be one initial network request.

If a tune has just a few different versions, the page remains nice and zippy. But if a tune has lots of settings, the computation starts to add up. Converting all those settings from ABC to SVG starts to take a cumulative toll on the main thread.

I pondered ways to avoid that conversion step. Was there some way of pre-generating the SVGs on the server rather than doing it all on the client?

In theory, yes. I could spin up a headless browser, run the JavaScript and take a snapshot. But that’s a bit beyond my backend programming skills, so I’ve taken a slightly different approach.

The first time anyone hits a tune page, the ABCs getting converted to SVGs as usual. But now there’s one additional step. I grab the generated markup and send it as an Ajax payload to an endpoint on my server. That endpoint stores the sheetmusic as a file in a cache.

Next time someone hits that page, there’s a server-side check to see if the sheetmusic has been cached. If it has, send that down the wire embedded directly in the HTML.

The idea is that over time, most of the sheetmusic on the site will transition from being generated in the browser to being stored on the server.

So far it’s working out well.

Take a really popular tune like The Lark In The Morning. There are twenty settings, and each one has four parts. Previously that would have resulted in a few seconds of parsing and rendering time on the main thread. Now everything is delivered up-front.

I’m not out of the woods. A page like that with lots of sheetmusic and plenty of comments is going to have a hefty page weight and a large DOM size. I’ve still got a fair bit of main-thread work happening, but now the bulk of it is style and layout, whereas previously I had the JavaScript overhead on top of that.

I’ll keep working on it. But overall, the speed improvement is great. A typical tune page is now very speedy indeed.

It’s like a microcosm of web performance in general: respect your users’ time, network connection and battery life. If that means shifting the work from the browser to the server, do it!

Web Summer Camp in Croatia finished with an interesting discussion. It was labelled a town-hall meeting, but it was more like an Oxford debating club.

Two speakers had two minutes each to speak for or against a particular statement. Their stances were assigned to them so they didn’t necessarily believe what they said.

One of the propositions was something like:

In the future, sustainable design will be as important as UX or performance.

That’s a tough one to argue against! But that’s what Sophia had to do.

She actually made a fairly compelling argument. She said that real impact isn’t going to come from individual websites changing their colour schemes. Real impact is going to come from making server farms run on renewable energy. She advocated for political action to change the system rather than having the responsibility heaped on the shoulders of the individuals making websites.

It’s a fair point. Much like the concept of a personal carbon footprint started life at BP to distract from corporate responsibility, perhaps we’re going to end up navel-gazing into our individual websites when we should be collectively lobbying for real change.

It’s akin to clicktivism—thinking you’re taking action by sharing something on social media, when real action requires hassling your political representative.

I’ve definitely seen some examples of performative sustainability on websites.

For example, at the start of this particular debate at Web Summer Camp we were shown a screenshot of a municipal website that has a toggle. The toggle supposedly enables a low-carbon mode. High resolution images are removed and for some reason the colour scheme goes grayscale. But even if those measures genuinely reduced energy consumption, it’s a bit late to enact them only after the toggle has been activated. Those hi-res images have already been downloaded by then.

Defaults matter. To be truly effective, the toggle needs to work the other way. Start in low-carbon mode, and only download the hi-res images when someone specifically requests them. (Hopefully browsers will implement prefers-reduced-data soon so that we can have our sustainable cake and eat it.)

Likewise I’ve seen statistics bandied about around the energy-savings that could be made if we used dark colour schemes. I’m sure the statistics are correct, but I’d like to see them presented side-by-side with, say, the energy impact of Google Tag Manager or React or any other wasteful dependencies that impact performance invisibly.

That’s the crux. Most of the important work around energy usage on websites is invisible. It’s the work done to not add more images, more JavaScript or more web fonts.

And it’s not just performance. I feel like the more important the work, the more likely it is to be invisible: privacy, security, accessibility …those matter enormously but you can’t see when a website is secure, or accessible, or not tracking you.

I suspect this is why those areas are all frustratingly under-resourced. Why pour time and effort into something you can’t point at?

Now that I think about it, this could explain the rise of web accessibility overlays. If you do the real work of actually making a website accessible, your work will be invisible. But if you slap an overlay on your website, it looks like you’re making a statement about how much you care about accessibility (even though the overlay is total shit and does more harm than good).

I suspect there might be a similar mindset at work when it comes to interface toggles for low-carbon mode. It might make you feel good. It might make you look good. But it’s a poor substitute for making your website carbon-neutral by default.

You can split the web in many ways. Lionel Dricot wrote about one of those ways in a blog post called Splitting the Web. In it, he outlines an ever-increasing divide he sees on the web.

On the one hand you’ve got people experiencing the advertising-driven, tracking-addicted big players who provide a bloated and buggy user experience.

On the hand, you’ve got the more tech-savvy users with tracking blockers (misleadingly called ad blockers) using browsers and search engines that value privacy and performance.

It feels like everyone is now choosing its side. You can’t stay in the middle anymore. You are either dedicating all your CPU cycles to run JavaScript tracking you or walking away from the big monopolies. You are either being paid to build huge advertising billboards on top of yet another framework or you are handcrafting HTML.

Maybe the web is not dying. Maybe the web is only splitting itself in two.

This reminded me of a post by Chris. No, not The Great Divide, although that’s obviously relevant here. Chris wrote a post just yesterday called Other People’s Busted Software is an Opportunity:

One way to look at it is opportunity. If you make software that does work reliably, you’ve got a leg up. Even if your customers don’t tell you “I like your software because it always works”, they’ll feel it and make choices around knowing it.

I like that optimistic take. If the majority seems to be doubling down on more tracking, more JavaScript, and more enshittification, then there’s a potential opportunity there (acknowledging that you’ve still got to battle against inertia and sunk cost).

This reminds of a fantastic talk that Stuart gave a few years ago called Privacy could be the next big thing:

How do you end up shaping the world? By inventing a thing that the current incumbents can’t compete against. By making privacy your core goal. Because companies who have built their whole business model on monetising your personal information cannot compete against that. They’d have to give up on everything that they are, which they can’t do. Facebook altering itself to ensure privacy for its users… wouldn’t exist. Can’t exist. That’s how you win.

Web performance is an unalloyed good. No one has ever complained that a website is too fast.

So the benefit is pretty obvious. Users like fast websites. But there are other benefits to web performance. And they don’t all get equal airtime.

Business

A lot of good web performance practices come down to the first half of Postel’s Law: be conservative in what send. Images, fonts, JavaScript …remove what you don’t need and optimise the hell out of what’s left.

That can translate to savings. If you’re paying for the bandwidth every time a hefty file is downloaded, your monthly bill could get pretty big.

So apart from the indirect business benefits of happy users converting to happy customers, there can be a real nuts’n’bolts bottom-line saving to be made by having a snappy website.

Sustainability

This is related to the cost-savings benefit. If you’re shipping less stuff down the wire, and you’re optimising what you do send, then there’s less energy required.

Whether less energy directly translates to a smaller carbon footprint depends on how the energy is being generated. If your servers are running on 100% renewable energy sources, then reducing the output of your responses won’t reduce your carbon footprint.

But there’s an energy cost at the other end too. Think of all the devices making requests to your server. If you’re making those devices work hard—by downloading, parsing, executing lots of JavaScript, for example—then you’re draining battery life. And you can’t guarantee that the battery will be replenished from renewable energy sources.

That’s why sites like the website carbon calculator have so much crossover with web performance:

From data centres to transmission networks to the billions of connected devices that we hold in our hands, it is all consuming electricity, and in turn producing carbon emissions equal to or greater than the global aviation industry. Yikes!

Inclusivity

There comes a point when a slow website isn’t just inconvenient, it’s inaccessible.

I’ve always liked the German phrase for accessible: barrierefrei—free of barriers. With every file you add to a website’s dependencies, you’re adding one more barrier. Eventually the barrier is insurmountable for people with older devices or slower internet connections. If they can no longer access your website, your website is quite literally inaccessible.

Making the case

I’ve noticed that when it comes to making the argument in favour of better web performance, people often default to the business benefits.

I get it. We’re always being told to speak the language of business. The psychology seems pretty straightforward; if you think that the people you’re trying to convince are mostly concerned with the bottom line, use the language of commerce to change their minds.

But that’s always felt reductive to me.

Sure, those people almost certainly do care about the business. Who doesn’t? But they’re also humans. I feel like if really want to convince them, speak to their hearts. Show them the bigger picture.

Eliel Saarinen said:

Always design a thing by considering it in its next larger context; a chair in a room, a room in a house, a house in an environment, an environment in a city plan.

I think the same could apply to making the case for web performance. Don’t stop at the obvious benefits. Go wider. Show the big-picture implications.

A recurring theme in my writing and talks is “lay off the JavaScript, people!” But I have to make a conscious effort to specify that I mean client-side JavaScript.

I thought it would be obvious from the context that I was talking about the copious amounts of JavaScript being shipped to end users to download, parse, and execute. But nothing’s ever really obvious. If I don’t explicitly say JavaScript in the browser, then someone inevitably thinks I’m having a go at JavaScript, the language.

I have absolutely nothing against JavaScript the language. Just like I have nothing against Python or Ruby or any other language that you might write with on your machine or your web server. But as soon as you deliver bytes over the wire, I start having opinions. It just so happens that JavaScript is the universal language for client-side coding so that’s why I call for restraint with JavaScript specifically.

There was a time when JavaScript only existed in web browsers. That changed with Node. Now it’s possible to write code for your web server and code for web browsers using the same language. Very handy!

But just because it’s the same language doesn’t mean you should treat it the same in both circumstance. As Remy puts it:

There are two JavaScripts.

One for the server - where you can go wild.

One for the client - that should be thoughtful and careful.

I was reading something recently that referred to Eleventy as a JavaScript library. It really brought me up short. I mean, on the one hand, yes, it’s a library of code and it’s written in JavaScript. It is absolutely technically correct to call it a JavaScript library.

But in my mind, a JavaScript library is something you ship to web browsers—jQuery, React, Vue, and so on. Whereas Eleventy executes its code in order to generate HTML and that’s what gets sent to end users. Conceptually, it’s like the opposite of a JavaScript library. Eleventy does its work before any user requests a URL—JavaScript libraries do their work after a user requests a URL.

To me it seems obvious that there should an entirely different mindset for writing code intended for a web browser. But nothing’s ever really obvious.

I remember when Node was getting really popular and npm came along as a way to manage all the bundles of code that people were assembling in their Node programmes. Makes total sense. But then I thought I heard about people using npm to do the same thing for client-side code. “That can’t be right!” I thought. I must’ve misunderstood. So I talked to someone from npm and explained how I must be misunderstanding something.

But it turned out that people really were treating client-side JavaScript no different than server-side JavaScript. People really were pulling in megabytes of other people’s code to ship to end users so that they could, I dunno, left pad numbers or something.

Listen, I don’t care what you get up to in the privacy of your own codebase. But don’t poison the well of the web with profligate client-side JavaScript.

I remember trying to convince people to use semantic markup because it’s good for accessibility. That tactic didn’t always work. When it didn’t, I would add “By the way, Google’s searchbot is indistinguishable from a screen-reader user so semantic markup is good for SEO.”

That usually worked. It always felt unsatisfying though. I don’t know why. It doesn’t matter if people do the right thing for the wrong reasons. The end result is what matters. But still. It never felt great.

It happened with responsive design and progressive enhancement too. If I couldn’t convince people based on user experience benefits, I’d pull up some official pronouncement from Google recommending those techniques.

Even AMP, a dangerously ill-conceived project, has one very handy ace in the hole. You can’t add third-party JavaScript cruft to AMP pages. That’s useful:

Beleaguered developers working for publishers of big bloated web pages have a hard time arguing with their boss when they’re told to add another crappy JavaScript tracking script or bloated library to their pages. But when they’re making AMP pages, they can easily refuse, pointing out that the AMP rules don’t allow it. Google plays the bad cop for us, and it’s a very valuable role.

AMP is currently dying, which is good news. Google have announced that core web vitals will be used to boost ranking instead of requiring you to publish in their proprietary AMP format. The really good news is that the political advantage that came with AMP has also been ported over to core web vitals.

Take user-hostile obtrusive overlays. Perhaps, as a contientious developer, you’ve been arguing for years that they should be removed from the site you work on because they’re so bad for the user experience. Perhaps you have been met with the same indifference that I used to get regarding semantic markup.

Well, now you can point out how those annoying overlays are affecting, for example, the cumulative layout shift for the site. And that number is directly related to SEO. It’s one thing for a department to over-ride UX concerns, but I bet they’d think twice about jeopardising the site’s ranking with Google.

I know it doesn’t feel great. It’s like dealing with a bully by getting an even bigger bully to threaten them. Still. Needs must.

Core web vitals from Google are the ingredients for an alphabet soup of exlusionary intialisms. But once you get past the unnecessary jargon, there’s a sensible approach underpinning the measurements.

From May—no, June—these measurements will be a ranking signal for Google search so performance will become more of an SEO issue. This is good news. This is what Google should’ve done years ago instead of pissing up the wall with their dreadful and damaging AMP project that blackmailed publishers into using a proprietary format in exchange for preferential search treatment. It was all done supposedly in the name of performance, but in reality all it did was antagonise users and publishers alike.

Core web vitals are an attempt to put numbers on user experience. This is always a tricky balancing act. You’ve got to watch out for the McNamara fallacy. Harry has already started noticing this:

A new and unusual phenomenon: clients reluctant (even refusing) to fix performance issues unless they directly improve Vitals.

Once you put a measurement on something, there’s a danger of focusing too much on the measurement. Chris is worried that we’re going to see tips’n’tricks for gaming core web vitals:

This feels like the start of a weird new era of web performance where the metrics of web performance have shifted to user-centric measurements, but people are implementing tricky strategies to game those numbers with methods that, if anything, slightly harm user experience.

The map is not the territory. The numbers are a proxy for user experience, but it’s notoriously difficult to measure intangible ideas like pain and frustration. As Laurie says:

This is 100% the downside of automatic tools that give you a “score”. It’s like gameification. It’s about hitting that perfect score instead of the holistic experience.

And Ethan has written about the power imbalance that exists when Google holds all the cards, whether it’s AMP or core web vitals:

Google used its dominant position in the marketplace to force widespread adoption of a largely proprietary technology for creating websites. By switching to Core Web Vitals, those power dynamics haven’t materially changed.

We would do well to remember:

When you measure, include the measurer.

But if we’re going to put numbers to user experience, the core web vitals are a pretty good spread of measurements: largest contentful paint, cumulative layout shift, and first input delay.

(If you prefer using initialisms, remember that CFP is Certified Financial Planner, CLS is Community Legal Services, and FID is Flame Ionization Detector. Together they form CWV, Catholic War Veterans.)

There are three ways—that I know of—to associate styles with markup.

External CSS

This is probably the most common. Using a link element with a rel value of “stylesheet”, you point to a URL using the href attribute. That URL is a style sheet that is applied to the current document (“the relationship of the linked resource it is that is a ‘stylesheet’ for the current document”).

<link rel="stylesheet" href="/path/to/styles.css">

In theory you could associate a style sheet with a document using an HTTP header, but I don’t think many browsers support this in practice.

You can also pull in external style sheets using the @import declaration in CSS itself, as long as the @import rule is declared at the start, before any other styles.

@import url('/path/to/more-styles.css');

When you use link rel="stylesheet" to apply styles, it’s a blocking request: the browser will fetch the style sheet before rendering the HTML. It needs to know how the HTML elements will be painted to the screen so there’s no point rendering the HTML until the CSS is parsed.

Embedded CSS

You can also place CSS rules inside a style element directly in the document. This is usually in the head of the document.

<style>
element {
    property: value;
}
</style>

When you embed CSS in the head of a document like this, there is no network request like there would be with external style sheets so there’s no render-blocking behaviour.

You can put any CSS inside the style element, which means that you could use embedded CSS to load external CSS using an @import statement (as long as that @import statement appears right at the start).

<style>
@import url('/path/to/more-styles.css');
element {
    property: value;
}
</style>

But then you’re back to having a network request.

Inline CSS

Using the style attribute you can apply CSS rules directly to an element. This is a universal attribute. It can be used on any HTML element. That doesn’t necessarily mean that the styles will work, but your markup is never invalidated by the presence of the style attribute.

<element style="property: value">
</element>

Whereas external CSS and embedded CSS don’t have any effect on specificity, inline styles are positively radioactive with specificity. Any styles applied this way are almost certain to over-ride any external or embedded styles.

You can also apply styles using JavaScript and the Document Object Model.

element.style.property = 'value';

Using the DOM style object this way is equivalent to inline styles. The radioactive specificity applies here too.

Style declarations specified in external style sheets or embedded CSS follow the rules of the cascade. Values can be over-ridden depending on the order they appear in. Combined with the separate-but-related rules for specificity, this can be very powerful. But if you don’t understand how the cascade and specificity work then the results can be unexpected, leading to frustration. In that situation, inline styles look very appealing—there’s no cascade and everything has equal specificity. But using inline styles means foregoing a lot of power—you’d be ditching the C in CSS.

A common technique for web performance is to favour embedded CSS over external CSS in order to avoid the extra network request (at least for the first visit—there are clever techniques for caching an external style sheet once the HTML has already loaded). This is commonly referred to as inlining your CSS. But really it should be called embedding your CSS.

This language mix-up is not a hill I’m going to die on (that hill would be referring to blog posts as blogs) but I thought it was worth pointing out.

Imagine if you were told that fossil fuels were the only way of extracting energy. It would be an absurd claim. Not only are other energy sources available—solar, wind, geothermal, nuclear—fossil fuels aren’t even the most effecient source of energy. To say that you can’t have energy without burning fossil fuels would be pitifully incorrect.

And yet when it comes to online advertising, we seem to have meekly accepted that you can’t have effective advertising without invasive tracking. But nothing could be further from the truth. Invasive tracking is to online advertising as fossil fuels are to energy production—an outmoded inefficient means of getting substandard results.

Before the onslaught of third party cookies and scripts, online advertising was contextual. If I searched for property insurance, I was likely to see an advertisement for property insurance. If I was reading an article about pet food, I was likely to be served an advertisement for pet food.

Simply put, contextual advertising ensured that the advertising that accompanied content could be relevant and timely. There was no big mystery about it: advertisers just needed to know what the content was about and they could serve up the appropriate advertisement. Nice and straightforward.

Too straightforward.

What if, instead of matching the advertisement to the content, we could match the advertisement to the person? Regardless of what they were searching for or reading, they’d be served advertisements that were relevant to them not just in that moment, but relevant to their lifestyles, thoughts and beliefs? Of course that would require building up dossiers of information about each person so that their profiles could be targeted and constantly updated. That’s where cross-site tracking comes in, with third-party cookies and scripts.

This is behavioural advertising. It has all but elimated contextual advertising. It has become so pervasive that online advertising and behavioural advertising have become synonymous. Contextual advertising is seen as laughably primitive compared with the clairvoyant powers of behavioural advertising.

But there’s a problem with behavioural advertising. A big problem.

It doesn’t work.

First of all, it relies on mind-reading powers by the advertising brokers—Facebook, Google, and the other middlemen of ad tech. For all the apocryphal folk tales of spooky second-guessing in online advertising, it mostly remains rubbish.

Forget privacy: you’re terrible at targeting anyway:

None of this works. They are still trying to sell me car insurance for my subway ride.

Have you actually paid attention to what advertisements you’re served? Maciej did:

I saw a lot of ads for GEICO, a brand of car insurance that I already own.

I saw multiple ads for Red Lobster, a seafood restaurant chain in America. Red Lobster doesn’t have any branches in San Francisco, where I live.

Finally, I saw a ton of ads for Zipcar, which is a car sharing service. These really pissed me off, not because I have a problem with Zipcar, but because they showed me the algorithm wasn’t even trying. It’s one thing to get the targeting wrong, but the ad engine can’t even decide if I have a car or not! You just showed me five ads for car insurance.

And yet in the twisted logic of ad tech, all of this would be seen as evidence that they need to gather even more data with even more invasive tracking and surveillance.

It turns out that bizarre logic is at the very heart of behavioural advertising. I highly recommend reading the in-depth report from The Correspondent called The new dot com bubble is here: it’s called online advertising:

It’s about a market of a quarter of a trillion dollars governed by irrationality.

The benchmarks that advertising companies use – intended to measure the number of clicks, sales and downloads that occur after an ad is viewed – are fundamentally misleading. None of these benchmarks distinguish between the selection effect (clicks, purchases and downloads that are happening anyway) and the advertising effect (clicks, purchases and downloads that would not have happened without ads).

Suppose someone told you that they keep tigers out of their garden by turning on their kitchen light every evening. You might think their logic is flawed, but they’ve been turning on the kitchen light every evening for years and there hasn’t been a single tiger in the garden the whole time. That’s the logic used by ad tech companies to justify trackers.

Tracker-driven behavioural advertising is bad for users. The advertisements are irrelevant most of the time, and on the few occasions where the advertising hits the mark, it just feels creepy.

Tracker-driven behavioural advertising is bad for advertisers. They spend their hard-earned money on invasive ad tech that results in no more sales or brand recognition than if they had relied on good ol’ contextual advertising.

Tracker-driven behavioural advertising is very bad for the web. Megabytes of third-party JavaScript are injected at exactly the wrong moment to make for the worst possible performance. And if that doesn’t ruin the user experience enough, there are still invasive overlays and consent forms to click through (which, ironically, gets people mad at the legislation—like GDPR—instead of the underlying reason for these annoying overlays: unnecessary surveillance and tracking by the site you’re visiting).

Tracker-driven behavioural advertising is good for the middlemen doing the tracking. Facebook and Google are two of the biggest players here. But that doesn’t mean that their business models need to be permanently anchored to surveillance. The very monopolies that make them kings of behavioural advertising—the biggest social network and the biggest search engine—would also make them titans of contextual advertising. They could pivot from an invasive behavioural model of advertising to a privacy-respecting contextual advertising model.

The incumbents will almost certainly resist changing something so fundamental. It would be like expecting an energy company to change their focus from fossil fuels to renewables. It won’t happen quickly. But I think that it may eventually happen …if we demand it.

In the meantime, we can all play our part. Just as we can do our bit for the environment at an individual level by sorting our recycling and making green choices in our day to day lives, we can all do our bit for the web too.

The least we can do is block third-party cookies. Some browsers are now doing this by default. That’s good.

Blocking third-party JavaScript is a bit trickier. That requires a browser extension. Most of these extensions to block third-party tracking are called ad blockers. That’s a shame. The issue is not with advertising. The issue is with tracking.

Alas, because this software is labelled under ad blocking, it has led to the ludicrous situation of an ethical argument being made to allow surveillance and tracking! It goes like this: websites need advertising to survive; if you block the ads, then you are denying these sites revenue. That argument would make sense if we were talking about contextual advertising. But it makes no sense when it comes to behavioural advertising …unless you genuinely believe that online advertising has to be behavioural, which means that online advertising has to track you to be effective. Such a belief would be completely wrong. But that doesn’t stop it being widely held.

To argue that there is a moral argument against blocking trackers is ridiculous. If anything, there’s a moral argument to be made for installing anti-tracking software for yourself, your friends, and your family. Otherwise we are collectively giving up our privacy for a business model that doesn’t even work.

It’s a shame that advertisers will lose out if tracking-blocking software prevents their ads from loading. But that’s only going to happen in the case of behavioural advertising. Contextual advertising won’t be blocked. Contextual advertising is also more lightweight than behavioural advertising. Contextual advertising is far less creepy than behavioural advertising. And crucially, contextual advertising works.

That shouldn’t be a controversial claim: the idea that people would be interested in adverts that are related to the content they’re currently looking at. The greatest trick the ad tech industry has pulled is convincing the world that contextual relevance is somehow less effective than some secret algorithm fed with all our data that’s supposed to be able to practically read our minds and know us better than we know ourselves.

Y’know, if this mind-control ray really could give me timely relevant adverts, I might possibly consider paying the price with my privacy. But as it is, YouTube still hasn’t figured out that I’m not interested in Top Gear or football.

The next time someone is talking about the necessity of advertising on the web as a business model, ask for details. Do they mean contextual or behavioural advertising? They’ll probably laugh at you and say that behavioural advertising is the only thing that works. They’ll be wrong.

I know it’s hard to imagine a future without tracker-driven behavioural advertising. But there are no good business reasons for it to continue. It was once hard to imagine a future without oil or coal. But through collective action, legislation, and smart business decisions, we can make a cleaner future.

I posted something recently that I think might be categorised as a “shitpost”:

Most single page apps are just giant carousels.

Extreme, yes, but perhaps there’s a nugget of truth to it. And it seemed to resonate:

I’ve never actually seen anybody justify SPA transitions with actual business data. They generally don’t seem to increase sales, conversion, or retention.

For some reason, for SPAs, managers are all of a sudden allowed to make purely emotional arguments: “it feels snappier”

If businesses were run rationally, when somebody asks for an order of magnitude increase in project complexity, the onus would be on them to prove that it proportionally improves business results.

But I’ve never actually seen that happen in a software business.

A single page app architecture makes a lot of sense for interaction-heavy sites with lots of state to maintain, like twitter.com. But I’ve seen plenty of sites built as single page apps even though there’s little to no interactivity or state management. For some people, it’s the default way of building anything on the web, even a brochureware site.

It seems like there’s a consensus that single page apps may have long initial loading times, but then they have quick transitions between “pages” …just like a carousel really. But I don’t know if that consensus is based on reality. Whether you’re loading a page of HTML or loading a chunk of JSON, you’re still making a network request that will take time to resolve.

The argument for loading a chunk of JSON is that you don’t have to make any requests for the associated CSS and JavaScript—they’re already loaded. Whereas if you request a page of HTML, that HTML will also request CSS and JavaScript.

Leaving aside the fact that is literally what the browser cache takes of, I’ve seen some circular reasoning around this:

1. We need to create a single page app because our assets, like our JavaScript dependencies, are so large.
2. Why are the JavaScript dependencies so large?
3. We need all that JavaScript to create the single page app functionlity.

To be fair, in the past, the experience of going from page to page used to feel a little herky-jerky, even if the response times were quick. You’d get a flash of a white blank page between navigations. But that’s no longer the case. Browsers now perform something called “paint holding” which elimates the herky-jerkiness.

So now if your pages are a reasonable size, there’s no practical difference in user experience between full page refreshes and single page app updates. Navigate around The Session if you want to see paint holding in action. Switching to a single page app architecture wouldn’t improve the user experience one jot.

Except…

If I were controlling everything with JavaScript, then I’d also have control over how to transition between the “pages” (or carousel items, if you prefer). There’s currently no way to do that with full page changes.

This is the problem that Jake set out to address in his proposal for navigation transitions a few years back:

Having to reimplement navigation for a simple transition is a bit much, often leading developers to use large frameworks where they could otherwise be avoided. This proposal provides a low-level way to create transitions while maintaining regular browser navigation.

I love this proposal. It focuses on user needs. It also asks why people reach for JavaScript frameworks instead of using what browsers provide. People reach for JavaScript frameworks because browsers don’t yet provide some functionality: components like tabs or accordions; DOM diffing; control over styling complex form elements; navigation transitions. The problems that JavaScript frameworks are solving today should be seen as the R&D departments for web standards of tomorrow. (And conversely, I strongly believe that the aim of any good JavaScript framework should be to make itself redundant.)

I linked to Jake’s excellent proposal in my shitpost saying:

bucketloads of JavaScript wouldn’t be needed if navigation transitions were available in browsers

But then I added—and I almost didn’t—this:

(not portals)

Now you might be asking yourself what Paul said out loud:

Excuse my ignorance but… WTF are portals!?

I replied with a link to the portals proposal and what I thought was an example use case:

Portals are a proposal from Google that would help their AMP use case (it would allow a web page to be pre-rendered, kind of like an iframe).

That was based on my reading of the proposal:

…show another page as an inset, and then activate it to perform a seamless transition to a new state, where the formerly-inset page becomes the top-level document.

It sounded like Google’s top stories carousel. And the proposal goes into a lot of detail around managing cross-origin requests. Again, that strikes me as something that would be more useful for a search engine than a single page app.

But Jake was not happy with my description. I didn’t intend to besmirch portals by mentioning Google AMP in the same sentence, but I can see how the transitive property of ickiness would apply. Because Google AMP is a nasty monopolistic project that harms the web and is an embarrassment to many open web advocates within Google, drawing any kind of comparison to AMP is kind of like Godwin’s Law for web stuff. I know that makes it sounds like I’m comparing Google AMP to Hitler, and just to be clear, I’m not (though I have myself been called a fascist by one of the lead engineers on AMP).

Clearly, emotions run high when Google AMP is involved. I regret summoning its demonic presence.

After chatting with Jake some more, I tried to find a better use case to describe portals. Reading the proposal, portals sound a lot like “spicy iframes”. So here’s a different use case that I ran past Jake: say you’re on a website that has an iframe embedded in it—like a YouTube video, for example. With portals, you’d have the ability to transition the iframe to a fully-fledged page smoothly.

But Jake told me that even though the proposal talks a lot about iframes and cross-origin security, portals are conceptually more like using rel="prerender" …but then having scripting control over how the pre-rendered page becomes the current page.

Put like that, portals sound more like Jake’s original navigation transitions proposal. But I have to say, I never would’ve understood that use case just from reading the portals proposal. I get that the proposal is aimed more at implementators than authors, but in its current form, it doesn’t seem to address the use case of single page apps.

Kenji said:

we haven’t seen interest from SPA folks in portals so far.

I’m not surprised! He goes on:

Maybe, they are happy / benefits aren’t clear yet.

From my own reading of the portals proposal, I think the benefits are definitely not clear. It’s almost like the opposite of Jake’s original proposal for navigation transitions. Whereas as that was grounded in user needs and real-world examples, the portals proposal seems to have jumped to the intricacies of implementation without covering the user needs.

Don’t get me wrong: if portals somehow end up leading to a solution more like Jake’s navigation transitions proposals, then I’m all for that. That’s the end result I care about. I’d love it if people had a lightweight option for getting the perceived benefits of single page apps without the costly overhead in performance that comes with JavaScripting all the things.

I guess the web I want includes giant carousels.

If you’re using web fonts, there are good performance (and privacy) reasons for hosting your own font files. And fortunately, Google Fonts gives you that option. There’s a “Download family” button on every specimen page.

But if you go ahead and download a font family from Google Fonts, you’ll notice something a bit odd. The .zip file only contains .ttf files. You can serve those on the web, but it’s far from the best choice. Woff2 is far leaner in file size.

This means you need to manually convert the downloaded .ttf files into .woff or .woff2 files using something like Font Squirrel’s generator. That’s fine, but I’m curious as to why this step is necessary. Why doesn’t Google Fonts provide .woff or .woff2 files in the downloaded folder? After all, if you choose to use Google Fonts as a third-party hosting service for your fonts, it most definitely serves up the appropriate file formats.

I thought maybe it was something to do with the licensing. Maybe some licenses only allow for unmodified truetype files to be distributed? But I’ve looked at fonts with different licenses—some have Apache 2 licensing, some have Open Font licensing—and they’re all quite permissive and definitely allow for modification.

Maybe the thinking is that, if you’re hosting your own font files, then you know what you’re doing and you should be able to do your own file conversion and subsetting. But I’ve come across more than one website in the wild serving up .ttf files. And who can blame them? They want to host their own font files. They downloaded those files from Google Fonts. Why shouldn’t they assume that they’re good to go?

It’s all a bit strange. If anyone knows why Google Fonts only provides .ttf files for download, please let me know. In a pinch, I will also accept rampant speculation.

Trys also pointed out some weird default behaviour if you do let Google Fonts do the hosting for you. Specifically if it’s a variable font. Let’s say it’s a font with weight as a variable axis. You specify in advance which weights you’ll be using, and then it generates separate font files to serve for each different weight.

Doesn’t that defeat the whole point of using a variable font? I mean, I can see how it could result in smaller file sizes if you’re just using one or two weights, but isn’t half the fun of having a weight axis that you can go crazy with as many weights as you want and it’s all still one font file?

Like I said, it’s all very strange.